Homo‐ and Heteroleptic Phototoxic Dinuclear Metallo‐Intercalators Based on RuII(dppn) Intercalating Moieties: Synthesis, Optical, and Biological Studies

Using a new mononuclear “building block,” for the first time, a dinuclear RuII(dppn) complex and a heteroleptic system containing both RuII(dppz) and RuII(dppn) moieties are reported. The complexes, including the mixed dppz/dppn system, are 1O2 sensitizers. However, unlike the homoleptic dppn systems, the mixed dppz/dppn complex also displays a luminescence “switch on” DNA light‐switch effect. In both cisplatin sensitive and resistant human ovarian carcinoma lines the dinuclear complexes show enhanced uptake compared to their mononuclear analogue. Thanks to a favorable combination of singlet oxygen generation and cellular uptake properties all three of the new complexes are phototoxic and display potent activity against chemotherapeutically resistant cells. 2 for 1 on PDT: New dinuclear RuII(dppn) and mixed RuII(dppn)/RuII(dppz) complexes display much enhanced cellular uptake properties compared to simple RuII(dppz) analogues. They are phototoxic and are particularly potent against chemotherapeutically resistant cells. The luminescent RuII(dppn)/RuII(dppz) complex also offers potential as a theranostic lead.